Tool for trimming screw-threads.



' PATBIYTED MAR. 1, 1904.

W. E. CORKREY. TOOL FOR TRIMMIN'G SCREW THREADS.

APPLICATION FILED JULY 29. 1903.

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"I! KORE Patented March 1, 1904.

wInLIAM CORKREY, or BRAINERD, MINNESOTA.

TOOL FOR TRIMMING SCREW-THREADS.

SPEGIFICATIOK forming part of Letters Patent No. 753,826, dated March 1,19 04.

Application filed July 29, 1903. Serial No. 167,504. (No model.)

To all whom it may concern/.-

Be it known that I, WILLIAM E. CORKREY, a citizen of the United States,residing at Brainerd, in the county of Crow Wing and State of Minnesota,have invented certain new and useful Improvements in Tools for TrimmingScrew-Threads; and I do hereby declare the following to be a full,clear, and exact description of the invention, such as will enableothers skilledin the art to which it appertains to make and use thesame.

This invention relates to tools for the removal of surplus metal fromany round body, such as a screw-threaded stay-bolt for a boiler or anyother round bolt or shaft, whether screw-threaded or. not.

This invention consists in the novel cuttingtool hereinafter fullydescribed and claimed.

In the drawings, Figure 1 is a plan view of the tool. Fig. 2 is a sideview of the tool.

' Fig. 3 is a front view of the tool looking toward its edge. p

A is the shank of the cutting-tool, which is formed of a rectangularpiece of steel. This shank has a projection C at its middle part, whichhas a beveled cutting edge 0' on its front edge and a beveledcutting-edge d on one of I same side of the shank as the side cuttingedge d is slightly in rear of the plane of the gageshoulder B. This part6 is formed so as to clear the tops of the screw-threads of the boltwhen the gage-shoulder B touches the tops of the said screw-threads, andit is preferably beveled, so as to enable a good cutting edge to beformed at (Z, it being necessary that at least a portion of the part bebeveled in order to form the beveled cutting edge 03' in a satisfactorymanner. It is necessary to allow the plate A to extend at e in order togive strength and stiffness to the projection G.

A portion of a stay-bolt g is shown in dotted. lines in the drawings.Stay-bolts are usually screw-threaded for their full length, and

in order to makethem lighter it is desirable to remove the screw-threadsfrom their middle portions. The stay-bolt is revolved upon its axis inany. approved manner, and the tool is held in any suitable support andis fed forward against the stay-bolt. The cutting edge 0 cuts or trimsaway the screw-threads until the gage-shoulder B touches the tops of thescrew-threads of the stay-bolt. The, tool is then moved longitudinallyalong the stay-bolt and the surplus screw-threads are trimmed oif by theside cutting edge d. Any approved lathe may be used, and thelongitudinal movement of the tool may be effected by the usualfeed-screw. A plurality of these tools may I also be used and they maybe arranged to operate simultaneously by securing them in any,

approved form of bolt-cutter die-head.

The dotted line 3 in Fig. 1 shows the junction of the gage with thecutting portion of the tool. The gage may be formed integral with thecutting part, or it may be welded to it, or it may be connected to it inany other approved manner. 7 When the tool is made of a single piece ofsteel, the gage-shoulder is ground back as the cutting edge 0 wears awayin use. When the tool is made in two pieces, the portion which forms thegage is slid back instead of being ground as the cutting edge 0 wearsaway.

What I claim is A cutting-tool provided with a blunt gage or stop uponits forward end, the cuttingportion projecting forwardly beyond the saidstop and having a cutting edge upon its forward end and upon its sideopposite the said stop.

In testimony whereof I aifix my signature in presence .of two witnesses.

WILLIAM n-ooakiuer.

Witnesses: V

W. N. PURDY, W. H. MAN'roR.

